Adding same-sex marriage law data to a d3-cartogram

Shawn Allen wrote a d3.js-based implementation of a 2D cartogram, which sizes US states in an area-proportional manner, where area is based on some interesting statistic, like population.

There has been a great deal of progress made in the last year in defending the rights of GLBT Americans to marry and have their partnership rights acknowledged, rights like visitation and estate planning, rights that straight couples take for granted when visiting their loved one in the hospital, or sharing their lives in the house they own, etc.

It’s easy enough to see a map of the 50 states colored by legal status, but people are not spread out evenly to live across all states. I wanted to see how the United States was progressing as a factor of population.

I forked Allen’s project (GitHub project source code available here) and I redid the color scheme, which takes the 50 states and the District of Columbia and shades them by their legal status, whether their laws defend or remove same-sex marriage rights (and associated protections).

Green states allow same-sex marriage, light-green states allow civil unions, orange allow marriage or civil unions (but rulings are currently held up on appeal), and red states that do not defend same-sex marriage rights, either by explicit law or constitutional amendment.

I based the color assignments initially on data from the Right to Marry site, up-to-date as of May 19th, 2014. But with Pennsylvania’s Gov. Corbett conceding defeat and vowing not to appeal the ruling, I added Pennsylvania to the list of pro-equality states.

In addition to seeing how fast things have changed, what is also interesting is that drawing by area quickly shows that over half the country — by 2010 US Census population counts, at least — now enjoys (or will soon enjoy, pending appeals) legal protections that were once denied to a minority of Americans.